JP2000030553A - Manufacture of high-frequency shielded cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a high-frequency shielded cable having an improved high-frequency characteristic. SOLUTION: When a plurality of conductive strips 13 are knitted on the outer periphery of a cable with dielectric material layer 1 to manufacture a cable with braid body 2, the tension (back tension) of the conductive strips 13 is set to 0.50-1.96 N, and a die 14 having the hole diameter not pressing or shrinking in the center direction is used. The delivery tension (back tension) is set to 3 N or below, the cable with braid body 2 is inserted into a molten metal tank, and a metal is stuck to a braided body to obtain a high-frequency shielded cable. Conductive strip bodies can be prevented from biting into a dielectric material layer, and the molten metal easily infiltrates into the braided body, thereby the high-frequency shielded cable excellent in a high-frequency characteristic can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a high-frequency shielded cable, and more particularly, to a method of manufacturing a high-frequency shielded cable improved so that high-frequency characteristics can be improved.

[0002]

2. Description of the Related Art A high-frequency shielded cable used for wiring of electronic equipment, communication equipment, and the like includes an inner conductor, a dielectric material layer formed on the outer periphery of the inner conductor, and an outer conductor formed on the outer periphery of the dielectric material layer. It is basically configured to include a conductor. As the types of the outer conductor, there are a braid in which a plurality of conductive strips are braided, a metal-attached braid in which a metal is adhered to the braid, and a metal pipe.

[0003]

Of the above high-frequency shielded cables, the high-frequency shielded cable using a braided outer conductor and the high-frequency shielded cable using a metal-adhered braided one cannot obtain high-frequency characteristics as designed. There was a problem. Accordingly, an object of the present invention is to provide a method of manufacturing a high-frequency shielded cable using a braided outer conductor and an improved high-frequency shielded cable using a metal-attached braid so as to improve the high-frequency characteristics. It is in.

[0004]

According to a first aspect, the present invention provides an internal conductor, a dielectric material layer formed on the outer periphery of the internal conductor, and an external conductor formed on the outer periphery of the dielectric material layer. Wherein the outer conductor is a braided body obtained by braiding a plurality of conductive bands or a metal-attached braided body obtained by attaching a metal to the braided body, wherein the dielectric material layer A method of manufacturing a high-frequency shielded cable, wherein when forming a braided body by knitting a plurality of conductive strips around the outer periphery of the cable, a tension (back tension) of the conductive strip is set to 0.50N to 1.96N. I will provide a.
The inventors of the present invention have conducted intensive studies and found that high-frequency shielded cables using a braided outer conductor and high-frequency shielded cables using a metal-attached braided body do not provide high-frequency characteristics as designed because of dielectric materials. It was found that the conductive band of the braid was cut into the layer, and the shape and dimensions of the outer conductor were not as designed. In addition, it was found that in a high-frequency shielded cable using a metal-attached braid for the outer conductor, metal was not sufficiently adhered to the braid.
Therefore, conventionally, in order to prevent the conductive band from jumping and to improve the appearance of the braided body, the tension of the conductive band is set to 4N to 6N. In the method, the tension of the conductive strip is set to 0.50 N or more.
1.96 N. As a result, the braid is loosened and the appearance of the braid is slightly deteriorated. However, the conductive band of the braid is prevented from biting into the dielectric material layer, and the high-frequency characteristics can be improved. Further, when the cable with the braid was passed through the molten metal bath, the molten metal easily penetrated into the braid, the metal was sufficiently adhered to the braid, and high-frequency characteristics could be improved. If the tension of the conductive band is smaller than 0.50 N, the conductive band cannot be knitted. Further, when the tension of the conductive strip is larger than 1.96 N, the conductive strip of the braided body may bite into the dielectric material layer.

According to a second aspect, the present invention provides the method of manufacturing a high-frequency shielded cable according to the first aspect, wherein a plurality of conductive strips are knitted around the dielectric material layer to form a braided body. And a method of manufacturing a high-frequency shielded cable using a die that does not press or reduce the diameter in the center direction. Conventionally, in order to improve the appearance of the braided body, a die that is pressed or reduced in diameter in the center direction has been used. However, in this case, the conductive band of the braided body penetrates the dielectric material layer. Therefore, in the method for manufacturing a high-frequency shielded cable according to the present invention according to the second aspect, a die which is not pressed or reduced in diameter in the center direction is used. This prevents the conductive band of the braid from penetrating into the dielectric material layer, thereby improving high-frequency characteristics.

[0006] In a third aspect, the invention provides an inner conductor,
A dielectric material layer formed on the outer periphery of the inner conductor, and an outer conductor formed on the outer periphery of the dielectric material layer, wherein the outer conductor adheres a metal to a braided body in which a plurality of conductive bands are woven. A method of manufacturing a high-frequency shielded cable, which is a metal-attached braided body, comprising a step of braiding a plurality of conductive strips around an outer periphery of the dielectric material layer to form a braided body, and forming a cable with a braided body. A method for producing a high-frequency shielded cable, comprising: when passing a cable with a braid through a molten metal bath to attach metal to the braid, setting a feeding tension (back tension) of the cable with the braid to 3N or less. provide. The inventors of the present invention have conducted intensive studies and found that high-frequency shielded cables using a metal-attached braid for the outer conductor cannot provide high-frequency characteristics as designed because metal is not sufficiently adhered to the braid. It turned out to be. Therefore, conventionally, in order to prevent the cable with a braided body from loosening or bouncing, the extension tension of the cable with the braided body that is passed through the molten metal tank is set to 9N to 10N. In the manufacturing method of (1), the feeding tension of the braided cable was set to 3N or less. Thereby, the amplitude of expansion and contraction of the braid at the time of unreeling increased, the molten metal easily penetrated into the braid, the metal sufficiently adhered to the braid, and high-frequency characteristics could be improved. In addition, when the extension tension of the cable with the braid is greater than 3N, the high-frequency characteristics may not be sufficiently improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited by this.

FIG. 1 is a schematic view of a braided cable manufacturing apparatus 100 for implementing the method of manufacturing a high-frequency shielded cable according to the present invention. The cable 1 with a dielectric material layer having an outer diameter of 2.85 mm is supplied from the reel 10, passes through the insertion hole at the center of the rotating disk 11, and enters the die 14.

As shown in FIG. 2, the cable 1 with a dielectric material layer comprises an inner conductor 4 made of copper and a dielectric material layer 5 made of polytetrafluoroethylene covering the outer periphery thereof.

Returning to FIG. 1, a plurality of conductive strip feeding devices 12 are circumferentially arranged on the rotating disk 11, and a plurality of copper strips are formed from the conductive strip feeding devices 12. The conductive band 13 has a tension (back tension) of 0.50 N to 1.
It is paid out at 96N.

FIG. 3A shows the conductive strip feeding device 1.
2 is a front view, and FIG. 3B is a cross-sectional side view of the conductive strip feeding device 12. The conductive strip 13 is supplied from a reel 30 and is fed out through a pressing roller 31, a tension roller 32, and a pressing roller 33. The reel 30 is braked by a brake mechanism 39 so as not to rotate unnecessarily. The tension roller 3
2 is supported by a tension arm 35, and the tension arm 35 is given a force by a spring 37 to rotate around a tension shaft 36. While checking with the push-pull gauge 40,
The tension of the conductive band 13 can be adjusted by adjusting the force 7 with the spring adjusting screw 38.

As shown in FIG. 4, a plurality of conductive strips 13 are provided.
Are braided together by the rotation of the rotating disks 11 on the outer periphery of the cable 1 with the dielectric material layer entering the dies 14 to form a braid (6 in FIG. 5). And the cable 1 with a dielectric material layer becomes the cable 2 with a braided body. The outer diameter of the braided cable 2 is 3.5 mm,
The diameter of the die hole 14a is 4.0 mm. In this way, a margin of 14% to 30% with respect to the outer diameter of the braided cable 2 is provided in the die hole so that the braided cable 2 is not pressed or reduced in the center direction by the die 14. It is preferable to have a hole diameter of 14a.

[0013] As shown in FIG.
Consists of an internal conductor 4 made of copper, a dielectric material layer 5 covering the outer periphery thereof, and a braided body 6 covering the outer periphery thereof. The braided cable 2 can be used as a high-frequency shielded cable as it is, but a metal is adhered to the braid 6 to improve high-frequency characteristics.

FIG. 6 is a schematic diagram of a high-frequency shielded cable manufacturing apparatus 200 for implementing the high-frequency shielded cable manufacturing method of the present invention. 3.5mm outer diameter braided cable 2
Is supplied from a reel 20 and enters a molten metal tank 21 in which molten tin or solder is stored.
Through the inside pulley 25, it exits the molten metal tank 21. The high-frequency shielded cable 3 passes through a drawing die 22 having a hole diameter of 3.5 mm, passes through a cooling device 23, and is wound around a reel 24.

A torque adjusting mechanism (permanent torque) 28 is attached to the reel 20. The unwinding tension of the cable 2 with a braid is adjusted by the torque adjusting mechanism 28 to be 0N to 3N.

The molten tin or solder enters the gaps between the braids 6 of the cable 2 with a braid entering the molten metal bath 21. The braid 6 expands and contracts before and after passing through the pulley 25, and the molten tin or solder permeates into the braid 6. Then, by passing through the drawing die 22, extra tin or solder attached is drawn out, and the outer diameter is made uniform. Further, the metal is solidified by the cooling device 23.

[0017] As shown in FIG.
Consists of a copper internal conductor 4, a polytetrafluoroethylene dielectric material layer 5 covering the outer periphery thereof, and a braided metal body 7 covering the outer periphery thereof.

The high-frequency shielded cable 3 manufactured as described above has a tension of 0.50N to 1.96N when the conductive band 13 is fed from the conductive band feeding device 12, so that the braiding is reduced. Conductive band 1 of braid 6
3 is prevented from digging into the dielectric material layer 5.
Also, since the braided cable 2 is not pressed or reduced in diameter in the center direction by the die 14, the conductive band 13 of the braid 6 is prevented from biting into the dielectric material layer 5 also in this point. Have been. Further, since the tension of the cable 2 with the braided body is set at 0N to 3N and is passed through the molten metal tank 21, the molten metal permeates the braided body 6 and adheres sufficiently. Therefore, high frequency characteristics can be improved. In addition, the cable 2 with a braid can be used as it is as a high frequency shielding cable. Even in this case, the conductive band 13 of the braided body 6 is prevented from biting into the dielectric material layer 5, so that high-frequency characteristics can be improved.

FIG. 8 shows that the tension of the conductive strip 13 is 1.67.
N shows the voltage standing wave ratio characteristics of the high-frequency shielded cable 3 of the embodiment in which the tension of the cable 2 with the braided body was set to 0 (free). For comparison, FIG. 9 shows the voltage standing wave ratio characteristics of the high-frequency shielded cable 3 when the tension of the conductive band 13 is 4.7 N and the extension tension of the braided cable 2 is 9.8 N. . As can be seen by comparing the two, the high-frequency shielded cable 3 according to the embodiment of the present invention can be understood.
In this example, the voltage standing wave ratio is always 1.1 or less, but in the comparative example, the voltage standing wave ratio exceeds 1.1 at 10 GHz to 15 GHz.

FIG. 10 shows that the tension of the conductive strip 13 is 1.6.
7 shows a return loss characteristic of the high-frequency shielded cable 3 of the embodiment in which the extension tension of the cable 2 with a braid is set to 0 (free). For comparison, FIG. 11 shows that the tension of the conductive band 13 was 4.7 N
9 shows the return loss characteristics of the high-frequency shielded cable 3 when the feeding tension is set to 9.8N. As can be seen by comparing the two, the high-frequency shielded cable 3 according to the embodiment of the present invention can be understood.
, The return loss is always -25 dB or less, but in the comparative example, the return loss is -25 dB at 10 GHz to 15 GHz.
Is over.

FIG. 12 shows a state in which the tension of the conductive band 13 is changed and the unwinding tension of the cable 2 with the braid is reduced to zero.
(Free) shows the voltage standing wave ratio characteristics of the high-frequency shielded cable 3. It can be seen that in order to make the voltage standing wave ratio 1.1 or less, the tension of the conductive strip 13 should be 1.96 N or less.

[0022]

According to the method for manufacturing a high-frequency shielded cable of the present invention, the following effects can be obtained. (1) When forming a braided body by knitting a plurality of conductive strips in a cable with a dielectric material layer, the feeding tension (back tension) of the conductive strips is 0.50 N to 1.1. 96N
By doing so, it is possible to prevent the conductive strip from biting into the dielectric material layer. Further, the molten metal easily permeates the braid. Therefore, a high-frequency shielded cable having excellent high-frequency characteristics can be obtained. (2) When forming a cable with a braided body, it is possible to prevent the conductive band from digging into the dielectric material layer by providing a margin to the cable outer diameter in the hole diameter of the die so as not to press or reduce the diameter. Further, the molten metal easily permeates the braid. Therefore, a high-frequency shielded cable having excellent high-frequency characteristics can be obtained. (3) When the cable with a braid is passed through a molten metal tank to attach metal, the braid can be expanded and contracted by setting the feeding tension (back tension) of the cable with the braid to 3 N or less. The molten metal easily penetrates into the inside. Further, it is possible to prevent the cable with a braid from contracting in the center direction. In this way, the metal penetrates to the inside of the braid, and the high-frequency shielding performance increases,
A high-frequency shielded cable having excellent high-frequency characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for manufacturing a cable with a braid for implementing a method for manufacturing a high-frequency shielded cable according to the present invention.

FIG. 2 is a sectional view of a cable with a dielectric material layer.

FIG. 3 is a front view and a cross-sectional side view of the conductive strip feeding device.

FIG. 4 is a schematic view showing a state in which the braided cable passes through a die. (The die is a sectional view.)

FIG. 5 is a sectional view of a cable with a braid.

FIG. 6 is a schematic view of a high-frequency shielded cable manufacturing apparatus for implementing the high-frequency shielded cable manufacturing method of the present invention.

FIG. 7 is a cross-sectional view of a high-frequency shielded cable.

FIG. 8 is a characteristic diagram of a voltage standing wave ratio of the high-frequency shielded cable according to the embodiment.

FIG. 9 is a characteristic diagram of a voltage standing wave ratio of a high-frequency shielded cable of a comparative example.

FIG. 10 is a characteristic diagram of the return loss of the high-frequency shielded cable according to the embodiment.

FIG. 11 is a characteristic diagram of the return loss of the high-frequency shielded cable of the comparative example.

FIG. 12 is a characteristic diagram of the tension of the conductive band and the voltage standing wave ratio.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Cable with dielectric material layer 2 Cable with braided body 3 High-frequency shielded cable 4 Inner conductor 5 Dielectric material layer 6 Braided body 7 Braided body with metal 12 Conductive strip feeding device 14 Dice 21 Molten metal tank 28 Torque adjustment mechanism 100 Braided cable manufacturing device 200 High-frequency shielded cable manufacturing device

Claims (3)

[Claims] An internal conductor, a dielectric material layer formed on an outer periphery of the internal conductor, and an external conductor formed on an outer periphery of the dielectric material layer, wherein the external conductor has a plurality of conductive strips. A method for manufacturing a high-frequency shielded cable, which is a braided body in which a metal is adhered to the braided body or a metal-adhered braided body in which a plurality of conductive bands are braided around the dielectric material layer Wherein the tension (back tension) of the conductive band is set to 0.50 N to 1.96 N when forming the high frequency shielding cable. 2. The method for manufacturing a high-frequency shielded cable according to claim 1, wherein a plurality of conductive strips are braided around the outer periphery of the dielectric material layer to form a braided body. A method for manufacturing a high-frequency shielded cable, comprising using a die having no diameter. 3. An inner conductor, a dielectric material layer formed on the outer periphery of the inner conductor, and an outer conductor formed on the outer periphery of the dielectric material layer, wherein the outer conductor has a plurality of conductive strips. A method for producing a high-frequency shielded cable, which is a metal-attached braid in which a metal is adhered to a braided braid, wherein a plurality of conductive strips are braided around the dielectric material layer to form a braid. After the braided cable is passed through the molten metal bath after the braided cable is attached to the braided body, the feeding tension (back tension) of the braided cable is set to 3N or less. Method for manufacturing a high-frequency shielded cable.